Dry cleaning process and compositions



United States Patent 3,294,6% DRY CLEANING PROCESS AND COMPOSITIONSMaurice Goharel, Saint-Auban, BflSSeS-AIPGS, Laurent Seigneurin,Salindres, Gard, France, and Lucien Hamelin (by France Hamelin,executrix for the estate of Lucien Hamelin), Vanves, Seine, France,assignors to Produits Chimiques Pechiney-Saint-Gobain, Neuillysur-Seine,France N0 )rawing. Filed May 18, 1964, Ser. No. 368,367 Claims priority,application France, May 20, 1963, 935,401 3 Claims. (Cl. 252172) Thisinvention relates to the art of dry cleaning and more particularly to adry cleaning process which makes use of a new and improved dry cleaningagent.

Among the well known dry cleaning solvents, present use is madeprincipally of tetrachlorethylene and trichlorethylene asrepresentative. These solvents have relatively high boiling points, suchthat in a normal cleaning cycle, which includes the following main stepsof washing, wringing, drying and deodorizing, the drying and deodorizingsteps consume a considerable amount of time.

Dichloroethylene has also been proposed for use in dry cleaning.However, dichloroethylene attacks certain synthetic and artificialmaterials formed into textile fibers and particularly fibers formed ofcellulose acetate and vinyl resins. Furthermore, dichloroethylene is notentirely non-inflammable and thus does not meet the safety requirements.

Certain chlorofiuorinated hydrocarbon derivatives formed of one or twocarbon atoms and having as many fluorine atoms as carbon atoms have alsobeen proposed. However, they present the deficiency in that theirboiling points are too low. In order to use them for dry cleaning, it isnecessary to make use of special machines adapted for use with suchvolatile solvents, and even with such specific devices, the losses whichmay take place during the cleaning cycle or in the storage and handlingof the solvent are excessive.

It is an object of this invention to provide a dry cleaning processwhich makes use of a dry cleaning agent that overcomes the deficienciesheretofore described and whereing the dry cleaning agent isnon-inflammable, is capable of being easily distilled, does not have toolow a boiling point and does not have any undesirable effects on thetextile fibers formed of synthetic or artificial resins.

In accordance with the practice of this invention, the dry cleaningprocess makes use of a new and improved dry cleaning agent consisting ofa liquid composition composed essentially of hexafiuorodichlorobutene orof a liquid composition containing hexafluorodichlorobutene as anessential and major ingredient. The term hexafluorodichlorobutene meansa compound having the formula C F Cl and which may comprise a mixture ofone or more of its isomers and particularly With the compositioncontaining hexafluorodichlorobutene, use can be made of one or moreother compounds in combination therewith selected from the group ofsolvents consisting of aliphatic hydrocarbon halogenated derivativeshaving a boiling point close to that of hexafiuorodichlorobutene, suchfor example as a halogenated aliphatic hydrocarbon derivative having aboiling point which does not deviate from the boiling point ofhexafiuorodichlorobutene by more than 25 to 30 C. and preferably by notmore than 15 C.

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The proportions of the constituents of said composition are selected soas to maintain, and preferably to improve, the required properties foruse in dry cleaning purposes.

' Thus during the distillation or re-distillation of such compositions,the initial proportions of the constituents will be maintained.

In addition to its non-inflammability, hexafluorodichlorobutene ischaracterized by being chemically stable, having a solvent powersutficiently high without having a tendency to attack the textile fibersor the buttons or plastic ornaments which are on the garments and it isalso free from odor.

In accordance with the practice of this invention, adjuvants can beincorporated in the usual small proportions with thehexafiuorodichlorobutene composition. Such adjuvants may be illustratedby the non-ionic, cationic or anionic tensio-active agents, reinforcingcleaning agents generally employed in the dry cleaning systems and inwhich such adjuvants preferably are selected to be compatible in thecomposition.

The compositions described find use also as a solvent for cleaning orfor degreasing in general and particularly for the cleaning of devicesfabricated of metals and insulating materials such as employed inelectric and telephone apparatus, motors, and the like.

It is also an object of this invention to provide a dry cleaning processwhich includes the step of washing the textile fibers and other garmentsby means of a liquid formed essentially of hexafiuorodichlorobutene orin which hexafiuor-odichlorobutene is an essential and major ingredient.

The following examples are given by way of illustration, but not by wayof limitation, of this invention.

EXAMPLES 1 TO 6 In a test for attack by hexafluorodichlorobutene,different textile fabrics made of cellulose triacetate, polyvinylchloride, polyamide 11, polyamide 6/6, polyacrylonitrile and glycolpolyterephthalate were immersed in hexafiuorodichlorobutene using 15volumes of the hexafluo-rodichlorobutene per part by weight of thefabric.

Textile fabrics made of cellulose triacetate and polyvinyl chloride areknown to be particularly sensitive to the action of organic solvents.For both of these fabrics, the fabrics were tested by immersion inhexafluorodichlorobutene for /2 hour at 20 C., for /2 hour at 30 C. andfor 4 hours at boiling point temperature using hexafluorodichlorobuteneunder reflux in a Soxhlet extractor. The results are set forth in thefollowing Table I.

For fabric materials other than formed of cellulose triacetate andpolyvinyl chloride, the attack tests were carried out in a Soxhletextractor at the boiling point temperaure of thehexafiuorodichlorobutene with exposure for 30 minutes.

In parallel tests, made for comparative purposes, the identical testswere carried out on identical fabrics in which trichloroethylene andtetrachloroethylene were used instead of the hexafiuorodichlorobutene.After treatment, the fabrics were dried and the following measurementswere made: a

(1) Dimensional stability calculated as shrinkage or lengtheningwarp-wise as Well as weft-wise of the fibers.

(2) Resistivity of the fabric to splitting.

In the following tables, the results of the tests are indicated. They:are expressed in percent variation with respect to the untreatedreference material. The values marked with the minus sign indicateshrinkage of the fabric sample while the plus sign indicateslengthening.

Table I Dimensional stability Resistance Conditions of treatment inpercent to bursting Nature of fabric samples of fabric samples Solventtests in percent Warp Weft 20 C. during an hour {$513311 g g "TEL? HFDB0 0 +2 Polyvinyl chloride 300 0' during an {ICE -0. 25 O. 25 +3. 4

. HFDB 0 -0.5 2.9 Bmhng durmg 4 hours m TCE or Attacked becomes Soxhletapparatusiron. hard and brittle.

C. during an l1our ggg g g 5 Cellulosic triacetate i w w Boiling during4 hours in {HEIDI}- -0. 75 l Soxhlet apparatus. PCE 12 -3 Table II 70%by weight of the composition. When other adjuvants are employed, it isundesirable to make use of Dimensional such adjuvants in an amount whichwill total more than Stabllltympercent Resistance 5% by weight of thecomposition and preferably less than Solvent bursting tests in percent2% by weight of the composition. The following will War? represent drycleaning compositions which may be employed in the practice of thisinvention: HFDB. 0 0 +0.9 P1Yam1de --{1 cE. -2.25 -1. 25 -5.3 EXAMPLE AHFDB +0.25 +1 -5.6 P 1yam defi/6* iPQEhn +0.75 +1.25 100% by weighthEXEIfiHOI'OdIChIOIObUtEDC Polyaerilonitrile B" 8 75 g 25 2 EXAMPLE B75% by weight hexafluorodichlorobutene Glycol polyter- {HFDB. o 0 +5.925% by weight difiuorodichloroethane ephthalate.* PCE -l. 75 l. 5 l0. 4

EXAMPLE C Treatment of fabric samples during 4 hours at the boilingpoint in the solvent into the Soxhlet extractor. 78% by wefghthexafluoFodchlorobutene 20% by weight difluorodichloroethane EXAMPLES 7To 10 1% by weight wetting agent Resin samples composed of polystyreneand of styrene 40 1% by weight surface active agent acrylonitrilecopolymers were submitted to the action of hexafluorodichlorobutene for.30 minutes at 20 C. and for 30 minutes at 30 C. Such resins are oftenused for making buttons and ornaments employed on garments. The weightvariation of the samples were determined by comparison to untreatedsamples.

Identical tests were carried out on the same resins withtetrachloroethylene.

The results are summarized in Table III in which the values having theminus sign indicate a loss in weight by comparison to a reference samplewhile values having the plus sign indicate swelling of the resin,indicative of attack.

It will be noticed that the hexafluorodichlorobutene is practically freefrom attack on the resins while the tetrachloroethylene stronglyattacks, particularly the polystyrene resins.

When the hexafluorodichlorobutene is employed in combination with otheraliphatic halogenated hydrocarbon derivatives, such asdifluorodichloroethane it is desirable to limit the amount of dilutionso that the hexafluorodichlorobutene will still constitute more than byWeight of the composition and preferably more than It will be understoodthat changes may be made in the details of formulation and applicationwithout departing from the spirit of the invention, especially asdefined in the following claims. I

We claim:

1. In a dry cleaning process for products containing some syntheticresinous materials, the step of washing the product with a liquidcomposition consisting essentially of at least 50 percent by weighthexafluorodichlorobutene as an essential and major ingredient with theremainder being formed essentially of an aliphatichalogenated drycleaning hydrocarbon having a boiling point within 30 C. of thehexafluorodichlorobutene and which is compatible therewith.

2. In a dry cleaning process, the step of treating the product to be drycleaned with a liquid composition consisting essentially ofhexafluorodichlorobutene.

3. The dry cleaning process as claimed in claim 1 in which thehe'xafluorodichlorobutene comprises more than 75 by Weight of the liquidcomposition.

References Cited by the Examiner UNITED STATES PATENTS 2,436,357 2/1948Gochenour et al. 260653.3 3,042,479 7/1962 Lawrence et al. 252l72 XROTHER REFERENCES Lovelace et al.: Aliphatic Fluorine Compounds, ReinholdPub. Corp., New York (1958) (pages 116-117 relied on).

LEON D. ROSDOL, Primary Examiner.

JULIUS GREENWALD, Examiner.

J. T. FEDIGAN, Assistant Examiner.

1. IN A DRY CLEANING PROCESS FOR PRODUCTS CONTAINING SOME SYNTHETICRESINOUS MATERIALS, THE STEP OF WASHING THE PRODUCT WITH A LIQUIDCOMPOSITION CONSISTING ESSENTIALLY OF AT LEAST 50 PERCENT BY WEIGHTHEXAFLUORODICHLOROBUTENE AS AN ESSENTIAL AND MAJOR INGREDIENT WITH THEREMAINDER BEING FORMED ESSENTIALLY OF AN ALIPHATIC HALOGENATED DRYCLEANING HYDROCARBON HAVING A BOILING POINT WITHIN 30*C. OF THEHEXAFLUORODICHLOROBUTENE AND WHICH IS COMPATIBLE THEREWITH.